Final answer:
William and Mary were crowned due to the Glorious Revolution, which peacefully deposed King James II. They were the first joint monarchs, accepting the throne with the condition of constitutional limits that enhanced Parliament's power. Their agreement included regularly summoning Parliament and requiring its consent for laws, taxation, and standing armies.
Step-by-step explanation:
William and Mary were crowned King and Queen of England as a result of the Glorious Revolution of 1688, which was a peaceful transfer of power that led to the overthrow of King James II, who was widely unpopular due to his Catholic faith and attempts to increase royal power. The ascension of William of Orange and his wife, Mary, to the English throne marked the first time in English history that monarchs would rule jointly. Their reign began under conditions that altered the traditional balance of power between the Crown and Parliament. William had insisted on a dual monarchy since he had a legitimate claim to the throne in his own right.
Their acceptance of the throne came with an agreement to adopt significant constitutional limitations which were laid out in the Bill of Rights 1689. This act established key principles that defined the future of constitutional monarchy in England: Parliament had to be summoned regularly, the royal power to suspend laws or raise revenue without Parliament's consent was illegal, and a standing army in peacetime required Parliamentary approval. Through these conditions, William and Mary accepted a monarchy that was ultimately subject to the laws passed by Parliament, ensuring a constitutional government.
Their reign also had a significant impact on the colonies, leading to new charters and the establishment of a new colonial order that helped precede the formation of Great Britain following the Act of Union under Queen Anne's rule.